[Scott Dorsey]

James Price wrote:
Compression is generally thought of as reducing dynamic range. However, let=
's say I've got a guitar amplifier that puts out pretty much the same volum=
e when I pick lightly in the entire range from "light" to "soft-medium" (us=
ing an arbitrary input scale from 0dB to 3dB). If I put a compressor post-a=
mp and side-chain it to my guitar input I could run it ducked whereby it's =
only active when the input is below 3dB on that arbitrary scale. Have I not=
expanded the lower threshold of my dynamic range?

With a compressor, the _more_ signal going into the sidechain input, the
more it compresses. So you can't set it up so it compresses below the
threshold and not above.

What you are describing is called an expander.

Many dbx compressors have expander functions, and there are some devices
out there that are generic dynamic control modules. Some of those get
called compressors rather than companders or dynamic controllers, even
though they can do far more than compress. This is because "Compressor"
is simple and easy to say and looks good on a tear sheet.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."